This invention relates to a massager which utilizes compressed air at a safe pressure and has a simple structure and easy operation.
As a device for effectively giving a pressure massage to the skin or muscles of a subject, there has existed a pressure-fluid massager provided with a bag means of rubber or the like, which is wound around a portion to be treated on the subject and expanded by supplying thereto a pressure fluid such as compressed air to exert massaging pressure upon the portion to be treated, thereby massaging the subject. In the massager of this type, to improve the massaging effect, the bag means is partitioned off into air-tight sections so that a pressure fluid can successively be fed into the air-tight sections by use of a distributing valve to give the massaging pressure to successive parts of the portion to be treated on the subject in consequence of the expansion of the bag means. Concrete examples are described in Japanese patent publication No. 41794/1976 and Japanese utility model publication No. 17673/1978.
The former item is distinguished by having four electromagnetic switching valves corresponding to four massaging bags, which valves are individually controlled by means of a rotary switch having of four contacts so as to successively supply compressed air to the respective bags. In the latter item, a supply of compressed air to four massaging bags is carried out by use of a set of four pilot valves for delivering the compressed air to the respective bags and another set of four transferring valves for controlling the aforesaid pilot valves. Such a complex mechanism depending on a complicated pipe arrangement is one serious drawback of these conventional massagers.
Besides, the massagers of this sort including the foregoing massagers make use of a rotary compressor of any type or a diaphragm-compressor as a means for producing pressure fluid of air or liquid. The application of the massager utilizing such a compressor to a living body has not been practical from the standpoint of safety inasmuch as the pressure difference between the rated pressure and the maximum pressure of the compressor is relatively large, thereby entailing the possibility of the pressure produced by the compressor becoming too high. To cope with such a disadvantage, the conventional massager has been provided with relief valves and regulator valves to ensure a safe pressure for massaging the subject, but involving the dangers of an accident to the valves.